This research investigates the relationship between hardness and microstructure obtained through SEM-EDS analysis of palm oil waste-based biocoke.The mechanical qualities and chemical composition of biocoke are being ...This research investigates the relationship between hardness and microstructure obtained through SEM-EDS analysis of palm oil waste-based biocoke.The mechanical qualities and chemical composition of biocoke are being studied concerning the influence of temperature conditions.The manufacturing temperature of biocoke may vary between 150℃ and 190℃.Utilizing SEM-EDS,we were able to characterize the microstructure and analyze the elemental composition,while the Hardness Shore D approach was used for the most complex materials.These results highlight the possibility of optimizing production temperature to produce biocoke with better mechanical performance.They show a positive correlation between biocoke hardness and structured carbon content.At 150℃ and 180℃,respectively,the EFB biocoke reached its maximum hardness level of 62±5.At 190℃,OPM biocoke generated a 60±5 times greater hardness than that of OPM and OPF biocoke.The OPT biocoke sample had the highest porosity with a score of 0.86,or 85.76%.Furthermore,compared to EFB biocoke,OPM and OPF biocokes had a priority of 0.84(84.20%)and 0.83(83.48%),respectively.Biocoke hardness is a quality indicator of physical and chemical qualities;the vital link between biocoke hardness,structural features,and elemental composition supports this idea.展开更多
Based on the daily maximum temperature data covering the period 1961-2005, temporal and spatial characteristics and their changing in mean annual and monthly high temperature days(HTDs)and the mean daily maximum tem...Based on the daily maximum temperature data covering the period 1961-2005, temporal and spatial characteristics and their changing in mean annual and monthly high temperature days(HTDs)and the mean daily maximum temperature(MDMT)during annual and monthly HTDs in East China were studied.The results show that the mean annual HTDs were 15.1 and the MDMT during annual HTDs was 36.3℃in the past 45 years.Both the mean annual HTDs and the MDMT during annual HTDs were negative anomaly in the1980s and positive anomaly in the other periods of time,oscillating with a cycle of about 12-15 years.The mean annual HTDs were more in the southern part,but less in the northern part of East China.The MDMT during annual HTDs was higher in Zhejiang,Anhui and Jiangxi provinces in the central and western parts of East China.The high temperature process(HTP) was more in the southwestern part,but less in northeastern part of East China.Both the HTDs and the numbers of HTP were at most in July,and the MDMT during monthly HTDs was also the highest in July.In the first 5 years of the 21st century,the mean annual HTDs and the MDMT during annual HTDs increased at most of the stations,both the mean monthly HTDs and the MDMT during monthly HTDs were positive anomalies from April to October,the number of each type of HTP generally was at most and the MDMT in each type of HTP was also the highest.展开更多
Uniaxial compression tests on sandstone samples with five different sizes after high temperature processes were performed in order to investigate the size effect and its evolution. The test results show that the densi...Uniaxial compression tests on sandstone samples with five different sizes after high temperature processes were performed in order to investigate the size effect and its evolution. The test results show that the density, longitudinal wave velocity, peak strength, average modulus and secant modulus of sandstone decrease with the increase of temperature, however, peak strain increases gradually. With the increase of ratio of height to diameter, peak strength of sandstone decreases, which has an obvious size effect. A new theoretical model of size effect of sandstone material considering the influence of temperature is put forward, and with the increase of temperature, the size effect is more apparent. The threshold decreases gradually with the increase of temperature, and the deviations of the experimental values and the theoretical values are between 0.44% and 6.06%, which shows quite a credibility of the theoretical model.展开更多
Effects of process and storage temperature on concentration of Maillard compounds in aseptic cold break tomato paste were evaluated during 12 months of storage time. Cold break tomato paste was processed at 104 ℃ or ...Effects of process and storage temperature on concentration of Maillard compounds in aseptic cold break tomato paste were evaluated during 12 months of storage time. Cold break tomato paste was processed at 104 ℃ or 112℃, aseptically filled into 5 liter bags, and stored at 21 ℃ and 33 ℃. Level of Browning Index, Furosine, and HMF was monitored in the aseptic cold break tomato paste during the storage time. Browning Index, Furosine, and HMF significantly increased in the aseptic cold break tomato paste during storage at 33℃, and there was linear correlation between Browning Index and Furosine (or HMF). At the lower storage temperature of 21℃, no significant increases were observed. Effects of the process temperature on Browning Index, Furosine, and HMF of aseptic cold break tomato paste were less significant than the storage temperature.展开更多
The microwave radiometer (MRM) onboard the Chang' E-1 (CE-I) lu- nar orbiter is a 4-frequency microwave radiometer, and it is mainly used to obtain the brightness temperature (TB) of the lunar surface, from whi...The microwave radiometer (MRM) onboard the Chang' E-1 (CE-I) lu- nar orbiter is a 4-frequency microwave radiometer, and it is mainly used to obtain the brightness temperature (TB) of the lunar surface, from which the thickness, temperature, dielectric constant and other related properties of the lunar regolith can be derived. The working mode of the CE-1 MRM, the ground calibration (including the official calibration coefficients), as well as the acquisition and processing of the raw data are introduced. Our data analysis shows that TB increases with increasing frequency, decreases towards the lunar poles and is significantly affected by solar illumination. Our analysis also reveals that the main uncertainty in TB comes from ground calibration.展开更多
Machined chips of Mg-Zn-Y-Zr alloy were consolidated by cold pressing and then hot extrusion under various processing temperatures and extrusion ratios. The results show that the microstructure of the chip-extruded al...Machined chips of Mg-Zn-Y-Zr alloy were consolidated by cold pressing and then hot extrusion under various processing temperatures and extrusion ratios. The results show that the microstructure of the chip-extruded alloy is marked by a large number of recrystallized grains and some unrecrystallized grains, which results in high strength but low ductility at temperatures below 320 ℃. With increasing processing temperature up to 360 ℃, entirely recrystallized and equiaxed grains are obtained. Mg-Zn-Y-Zr alloy with low strength but high ductility is obtained compared with the alloy processed at low temperature. At 420℃, coarse and equiaxed grains are formed, which results in the drastic decrease of mechanical properties. With increasing extrusion ratio from 8 to 16, the grain refinement is more obvious and the mechanical properties at room temperature are improved effectively. However, the yield strength and ultimate tensile strength are improved a little with further increasing extrusion ratio.展开更多
Flexible perovskite solar cells(FPSCs)are supposed to play an important role in the commercialization of perovskite solar cells due to their unique properties,such as high efficiency,thin thickness and being compatibl...Flexible perovskite solar cells(FPSCs)are supposed to play an important role in the commercialization of perovskite solar cells due to their unique properties,such as high efficiency,thin thickness and being compatible with roll to roll(R2R)process for mass production.At present,deformable and lightweight FPSCs have been successfully prepared and applied as power supply by integrating with different wearable and portable electronics,which opens a niche market for photovoltaics.In this mini review,we will introduce the recent progress of FPSCs from the aspect of small-area flexible devices,R2R processed devices with large scale and emerging flexible cells with deformability and stretchability.Finally,conclusion and outlook are provided.展开更多
The properties of yttria stabilized zirconia(YSZ) related to the sintering process were discussed.YSZ nano-powders about 40-100 nm as raw material,the sub-micrometer grain sizes such as 0.4-3 μm in YSZ were gotten ...The properties of yttria stabilized zirconia(YSZ) related to the sintering process were discussed.YSZ nano-powders about 40-100 nm as raw material,the sub-micrometer grain sizes such as 0.4-3 μm in YSZ were gotten by sintering process at 1300 ℃,which was performed at 1000 ℃ for 2 h,then raised the temperature at the rate of 50 ℃ / h to 1400 ℃,then decreased directly to 1300 ℃ in 30 minutes,finally at 1300 ℃ for 5-20 hours.The ratio of bigger grain size becomes larger as the holding time increasing at 1300 ℃.The grains less than 1 μm are about 50%,eg,43.2%,52.2% and 51.1% related to 1300 ℃ holding 5 hours,8 hours and 10 hours,respectively.As YSZ grain size became small,the electrical conductivities did not decrease,even increased,about 0.20 s/cm at 1000 ℃.The reduced sintering temperature and time were benefited to co-fire with the electrodes in electrode-supported SOFCs.展开更多
A lowtemperature coefficient( TC) bandgap reference( BGR) with novel process variation calibration technique is proposed in this paper. This proposed calibration technique compensating both TC and output value of ...A lowtemperature coefficient( TC) bandgap reference( BGR) with novel process variation calibration technique is proposed in this paper. This proposed calibration technique compensating both TC and output value of BGR achieves fine adjustment step towards the reference voltage,while keeping optimal TC by utilizing large resistance to help layout match. The high-order curvature compensation realized by poly and p-diffusion resistors is introduced into the design to guarantee the temperature characteristic. Implemented in 180 nm technology,the proposed BGR has been simulated to have a power supply rejection ratio( PSRR) of 91 dB@100 Hz. The calibration technique covers output voltage scope of 0. 49 V-0. 56 Vwith TC of 9. 45 × 10^(-6)/℃-9. 56 × 10^(-6)/℃ over the temperature range of-40 ℃-120 ℃. The designed BGR provides a reference voltage of 500 mV,with measured TC of 10. 1 × 10^(-6)/℃.展开更多
Technology development and continuous down scaling in CMOS fabrication makes Mixed Signal Integrated Circuits (MSIC) more vulnerable to process variation. This paper presents a well defined novel design methodology fo...Technology development and continuous down scaling in CMOS fabrication makes Mixed Signal Integrated Circuits (MSIC) more vulnerable to process variation. This paper presents a well defined novel design methodology for process variability aware design by incorporating the major challenge of statistical circuit performance relating the device and circuit level variation in an accurate and efficient manner to improve the reliability, robustness and stability of the circuit. The device sensitive parameters are identified and accurately quantified by continuous realistic assessments using statistical methods. The modularity of the methodology can be validated by the output performance obtained from the gain and phase response of OTA which is highly stable when subjected to worst case process variation scenario. In the proposed optimization, the circuit is strengthened by fixing the optimum aspect ratio without adding any additional compensation devices complicating the circuit resulting in low power consumption of only 0.116 mW in standard CMOS 0.18 μm technology with 1.8 V power supply.展开更多
Isothermal compression testing of Ti555211 titanium alloys was carried out at deformation temperatures from 750 to 950 °C in 50 °C intervals with a strain rate of0.001-1.000 s^(-1). The high-temperature de...Isothermal compression testing of Ti555211 titanium alloys was carried out at deformation temperatures from 750 to 950 °C in 50 °C intervals with a strain rate of0.001-1.000 s^(-1). The high-temperature deformation behavior of the Ti555211 alloy was characterized by analysis of stress-strain behavior, kinetics and processing maps. A constitutive equation was formulated to describe the flow stress as a function of deformation temperature and strain rate, and the calculated apparent activation energies are found to be 454.50 and 207.52 k J mol^(-1)in the a b-phase and b-phase regions, respectively. A processing map based on the Murty instability criterion was developed at a strain of 0.7. The maps exhibit two domains of peak efficiency from 750 to 950 °C. A *60 % peak efficiency occurs at 800-850 °C/0.001-0.010 s^(-1). The other peak efficiency of *60 % occurs at C950 °C/0.001-0.010 s^(-1), which can be considered to be the optimum condition for high-temperature working of this alloy.However, at strain rates of higher than 1.000 s^(-1)and deformation temperatures of 750 and 950 °C, clear process flow lines and bands of flow localization occur in the hightemperature deformation process, which should be avoided in Ti555211 alloy hot processing. The mechanism in stability domain and instability domain was also discussed.展开更多
Cu_2NiSnS_4 nanoparticles were prepared for the first time using a facile solid-phase process at a temperature of 180 °C. The crystalline structure, morphology and optical properties of the Cu_2NiSnS_4 nanopartic...Cu_2NiSnS_4 nanoparticles were prepared for the first time using a facile solid-phase process at a temperature of 180 °C. The crystalline structure, morphology and optical properties of the Cu_2NiSnS_4 nanoparticles were characterized by means of X-ray diffraction(XRD), field emission scanning electron microscopy(FESEM), transmission electron microscope(TEM) and ultraviolet-visible(UV-vis) spectrophotometer. The band gap and conversion efficiency of Cu_2NiSnS_4 nanoparticles were studied at various temperature. The results showed that the Cu_2NiSnS_4 nanoparticles exhibited an optimum band gap of 1.58 e V and a conversion efficiency of 0.64% at 180 °C, indicating that it maybe be useful in low-cost thin film solar cells.展开更多
The relationship between microstructure evolution and coefficient of thermal expansion (CTE) of 7A09 aluminum alloy was investigated in this paper. Differential scanning calorimetry (DSC) was combined with transmi...The relationship between microstructure evolution and coefficient of thermal expansion (CTE) of 7A09 aluminum alloy was investigated in this paper. Differential scanning calorimetry (DSC) was combined with transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM) to investigate microstructure evolution taking place in 7A09 aluminum alloy during heating and cooling process. The corresponding CTE curves of the 7A0g alloy were recorded by thermal dilatometer. Results indicated that GPII zones and Ur phase were main precipitates in the highest strength tempered (T6) 7A09 alloy. The r/phase was the main participate in 7A09 alloy during the cooling process. The nonlinear dependency existed between CTE and temperature in both changing temperature processes. During the heating process, obvious additional contraction of alloy volume was directly caused by phase transition, such as dissolution of η' phase, transition from η' to η phase and dissolution of η phase. The additional contraction could slow down the increase of CTE greatly and be expressed in the nonlinearity of CTE curve. Volume and energy changes of alloy system influenced the variation trend of CTE directly, which was caused by the precipitation of U phase during the cooling process. These effects were revealed by the corresponding nonlinear change of CTE.展开更多
Since pyrometallurgical approaches on lithium ion battery recycling are not yet capable of recovering lithium but only nickel,cobalt and manganese,the Chair of Thermal Processing Technology at the Montanuniversitaet L...Since pyrometallurgical approaches on lithium ion battery recycling are not yet capable of recovering lithium but only nickel,cobalt and manganese,the Chair of Thermal Processing Technology at the Montanuniversitaet Leoben started to investigate experimental reactor concepts on their suitability to overcome this major drawback.Therefor,the general behaviour of currently used cathode materials under reducing conditions and high temperatures is of great interest.This work expands previous performed heating microscope experiments by thermogravimetric analysis(TGA)to characterize the reactions that are responsible for certain changes in the cathode materials.By comparing the superficial changes of the samples in the heating microscope with the corresponding data from the TGA,it was possible to identify the temperature zones in which reduction reactions occured.For all investigated cathode materials,the reduction reactions started at technically feasible temperatures of approx.1000◦C,which is favorable for the desired recycling process.On the other hand,this is some hundred degrees higher than the temperature at which first changes in the heating microscope could be observed and indicates that there are changes in the material before the reduction starts.Therefore,the results also emphasize the need for further analysis to clarify this offset and to complete the thermal characterisation of the cathode materials.展开更多
Using the multiple-parameter Monte Carlo method, the effectiveness of the dual threshold voltage technique (DTV) in low power domino logic design is analyzed. Simulation results indicate that under significant tempe...Using the multiple-parameter Monte Carlo method, the effectiveness of the dual threshold voltage technique (DTV) in low power domino logic design is analyzed. Simulation results indicate that under significant temperature and process fluctuations, DTV is still highly effective in reducing the total leakage and active power consumption for domino gates with speed loss. Also, regarding power and delay characteristics, different structure domino gates with DTV have different robustness against temperature and process fluctuation.展开更多
This paper presents the design and measured performance ofa wideband amplifier for a direct conversion satellite tuner. It is composed of a wideband low noise amplifier (LNA) and a two-stage RF variable gain amplifi...This paper presents the design and measured performance ofa wideband amplifier for a direct conversion satellite tuner. It is composed of a wideband low noise amplifier (LNA) and a two-stage RF variable gain amplifier (VGA) with linear gain in dB and temperature compensation schemes. To meet the system linearity requirement, an improved distortion compensation technique and a bypass mode are applied on the LNA to deal with the large input signal. Wideband matching is achieved by resistive feedback and an off-chip LC-ladder matching network. A large gain control range (over 80 dB) is achieved by the VGA with process voltage and temperature compensation and dB linearization. In total, the amplifier consumes up to 26 mA current from a 3.3 V power supply. It is fabricated in a 0.35μm SiGe BiCMOS technology and occupies a silicon area of 0.25 mm^2.展开更多
The 10MW high temperature gas-cooled reactor test module (HTR-10) is currently under construction.One of its objectives is to develop high temperature process heat applications. To realize this target, various high te...The 10MW high temperature gas-cooled reactor test module (HTR-10) is currently under construction.One of its objectives is to develop high temperature process heat applications. To realize this target, various high temperature gas-cooled reactor (HTGR) process heat applications have been analyzed. This paper briefly describes the possibilities and experimental schemes for using the HTR-10 for process heat application studies.展开更多
基金support from Cisitu Advanced Characterization Laboratories and the National Research and Innovation Agency through E-Layanan Sains-BRIN.
文摘This research investigates the relationship between hardness and microstructure obtained through SEM-EDS analysis of palm oil waste-based biocoke.The mechanical qualities and chemical composition of biocoke are being studied concerning the influence of temperature conditions.The manufacturing temperature of biocoke may vary between 150℃ and 190℃.Utilizing SEM-EDS,we were able to characterize the microstructure and analyze the elemental composition,while the Hardness Shore D approach was used for the most complex materials.These results highlight the possibility of optimizing production temperature to produce biocoke with better mechanical performance.They show a positive correlation between biocoke hardness and structured carbon content.At 150℃ and 180℃,respectively,the EFB biocoke reached its maximum hardness level of 62±5.At 190℃,OPM biocoke generated a 60±5 times greater hardness than that of OPM and OPF biocoke.The OPT biocoke sample had the highest porosity with a score of 0.86,or 85.76%.Furthermore,compared to EFB biocoke,OPM and OPF biocokes had a priority of 0.84(84.20%)and 0.83(83.48%),respectively.Biocoke hardness is a quality indicator of physical and chemical qualities;the vital link between biocoke hardness,structural features,and elemental composition supports this idea.
基金Funded by R&D Special Fund for Public Welfare Industry(meteorology),No.GYHY(QX)2007-6-19Na-tional Scientific and Technical Supporting Programs,No.2006BAK13B05
文摘Based on the daily maximum temperature data covering the period 1961-2005, temporal and spatial characteristics and their changing in mean annual and monthly high temperature days(HTDs)and the mean daily maximum temperature(MDMT)during annual and monthly HTDs in East China were studied.The results show that the mean annual HTDs were 15.1 and the MDMT during annual HTDs was 36.3℃in the past 45 years.Both the mean annual HTDs and the MDMT during annual HTDs were negative anomaly in the1980s and positive anomaly in the other periods of time,oscillating with a cycle of about 12-15 years.The mean annual HTDs were more in the southern part,but less in the northern part of East China.The MDMT during annual HTDs was higher in Zhejiang,Anhui and Jiangxi provinces in the central and western parts of East China.The high temperature process(HTP) was more in the southwestern part,but less in northeastern part of East China.Both the HTDs and the numbers of HTP were at most in July,and the MDMT during monthly HTDs was also the highest in July.In the first 5 years of the 21st century,the mean annual HTDs and the MDMT during annual HTDs increased at most of the stations,both the mean monthly HTDs and the MDMT during monthly HTDs were positive anomalies from April to October,the number of each type of HTP generally was at most and the MDMT in each type of HTP was also the highest.
基金Project(2013CB036003)supported by the National Key Basic Research Program of ChinaProjects(51374198,51134001)supported by the National Natural Science Foundation of ChinaProject(CXZZ13_0935)supported by the Jiangsu Province Ordinary College Graduate Research Innovative Program,China
文摘Uniaxial compression tests on sandstone samples with five different sizes after high temperature processes were performed in order to investigate the size effect and its evolution. The test results show that the density, longitudinal wave velocity, peak strength, average modulus and secant modulus of sandstone decrease with the increase of temperature, however, peak strain increases gradually. With the increase of ratio of height to diameter, peak strength of sandstone decreases, which has an obvious size effect. A new theoretical model of size effect of sandstone material considering the influence of temperature is put forward, and with the increase of temperature, the size effect is more apparent. The threshold decreases gradually with the increase of temperature, and the deviations of the experimental values and the theoretical values are between 0.44% and 6.06%, which shows quite a credibility of the theoretical model.
文摘Effects of process and storage temperature on concentration of Maillard compounds in aseptic cold break tomato paste were evaluated during 12 months of storage time. Cold break tomato paste was processed at 104 ℃ or 112℃, aseptically filled into 5 liter bags, and stored at 21 ℃ and 33 ℃. Level of Browning Index, Furosine, and HMF was monitored in the aseptic cold break tomato paste during the storage time. Browning Index, Furosine, and HMF significantly increased in the aseptic cold break tomato paste during storage at 33℃, and there was linear correlation between Browning Index and Furosine (or HMF). At the lower storage temperature of 21℃, no significant increases were observed. Effects of the process temperature on Browning Index, Furosine, and HMF of aseptic cold break tomato paste were less significant than the storage temperature.
基金supported by the National Natural Science Foundation of China (Grant No. 11173038)
文摘The microwave radiometer (MRM) onboard the Chang' E-1 (CE-I) lu- nar orbiter is a 4-frequency microwave radiometer, and it is mainly used to obtain the brightness temperature (TB) of the lunar surface, from which the thickness, temperature, dielectric constant and other related properties of the lunar regolith can be derived. The working mode of the CE-1 MRM, the ground calibration (including the official calibration coefficients), as well as the acquisition and processing of the raw data are introduced. Our data analysis shows that TB increases with increasing frequency, decreases towards the lunar poles and is significantly affected by solar illumination. Our analysis also reveals that the main uncertainty in TB comes from ground calibration.
基金Project (51005217) supported by the National Natural Science Foundation of ChinaProject (20100480677) supported by China Postdoctoral Science Foundation
文摘Machined chips of Mg-Zn-Y-Zr alloy were consolidated by cold pressing and then hot extrusion under various processing temperatures and extrusion ratios. The results show that the microstructure of the chip-extruded alloy is marked by a large number of recrystallized grains and some unrecrystallized grains, which results in high strength but low ductility at temperatures below 320 ℃. With increasing processing temperature up to 360 ℃, entirely recrystallized and equiaxed grains are obtained. Mg-Zn-Y-Zr alloy with low strength but high ductility is obtained compared with the alloy processed at low temperature. At 420℃, coarse and equiaxed grains are formed, which results in the drastic decrease of mechanical properties. With increasing extrusion ratio from 8 to 16, the grain refinement is more obvious and the mechanical properties at room temperature are improved effectively. However, the yield strength and ultimate tensile strength are improved a little with further increasing extrusion ratio.
文摘Flexible perovskite solar cells(FPSCs)are supposed to play an important role in the commercialization of perovskite solar cells due to their unique properties,such as high efficiency,thin thickness and being compatible with roll to roll(R2R)process for mass production.At present,deformable and lightweight FPSCs have been successfully prepared and applied as power supply by integrating with different wearable and portable electronics,which opens a niche market for photovoltaics.In this mini review,we will introduce the recent progress of FPSCs from the aspect of small-area flexible devices,R2R processed devices with large scale and emerging flexible cells with deformability and stretchability.Finally,conclusion and outlook are provided.
基金Funded by the National Natural Science Foundation of China (NSFC)(No. 50730004)the New Century Elitist Project (No. NCET-06-0203)
文摘The properties of yttria stabilized zirconia(YSZ) related to the sintering process were discussed.YSZ nano-powders about 40-100 nm as raw material,the sub-micrometer grain sizes such as 0.4-3 μm in YSZ were gotten by sintering process at 1300 ℃,which was performed at 1000 ℃ for 2 h,then raised the temperature at the rate of 50 ℃ / h to 1400 ℃,then decreased directly to 1300 ℃ in 30 minutes,finally at 1300 ℃ for 5-20 hours.The ratio of bigger grain size becomes larger as the holding time increasing at 1300 ℃.The grains less than 1 μm are about 50%,eg,43.2%,52.2% and 51.1% related to 1300 ℃ holding 5 hours,8 hours and 10 hours,respectively.As YSZ grain size became small,the electrical conductivities did not decrease,even increased,about 0.20 s/cm at 1000 ℃.The reduced sintering temperature and time were benefited to co-fire with the electrodes in electrode-supported SOFCs.
基金Supported by the National Natural Science Foundation of China(61604109)the National High-Tech R&D Program of China(2015AA042605)
文摘A lowtemperature coefficient( TC) bandgap reference( BGR) with novel process variation calibration technique is proposed in this paper. This proposed calibration technique compensating both TC and output value of BGR achieves fine adjustment step towards the reference voltage,while keeping optimal TC by utilizing large resistance to help layout match. The high-order curvature compensation realized by poly and p-diffusion resistors is introduced into the design to guarantee the temperature characteristic. Implemented in 180 nm technology,the proposed BGR has been simulated to have a power supply rejection ratio( PSRR) of 91 dB@100 Hz. The calibration technique covers output voltage scope of 0. 49 V-0. 56 Vwith TC of 9. 45 × 10^(-6)/℃-9. 56 × 10^(-6)/℃ over the temperature range of-40 ℃-120 ℃. The designed BGR provides a reference voltage of 500 mV,with measured TC of 10. 1 × 10^(-6)/℃.
文摘Technology development and continuous down scaling in CMOS fabrication makes Mixed Signal Integrated Circuits (MSIC) more vulnerable to process variation. This paper presents a well defined novel design methodology for process variability aware design by incorporating the major challenge of statistical circuit performance relating the device and circuit level variation in an accurate and efficient manner to improve the reliability, robustness and stability of the circuit. The device sensitive parameters are identified and accurately quantified by continuous realistic assessments using statistical methods. The modularity of the methodology can be validated by the output performance obtained from the gain and phase response of OTA which is highly stable when subjected to worst case process variation scenario. In the proposed optimization, the circuit is strengthened by fixing the optimum aspect ratio without adding any additional compensation devices complicating the circuit resulting in low power consumption of only 0.116 mW in standard CMOS 0.18 μm technology with 1.8 V power supply.
基金financially supported by the Project of Introducing Talents of Discipline to Universities‘‘111’’Project(No.B08040)
文摘Isothermal compression testing of Ti555211 titanium alloys was carried out at deformation temperatures from 750 to 950 °C in 50 °C intervals with a strain rate of0.001-1.000 s^(-1). The high-temperature deformation behavior of the Ti555211 alloy was characterized by analysis of stress-strain behavior, kinetics and processing maps. A constitutive equation was formulated to describe the flow stress as a function of deformation temperature and strain rate, and the calculated apparent activation energies are found to be 454.50 and 207.52 k J mol^(-1)in the a b-phase and b-phase regions, respectively. A processing map based on the Murty instability criterion was developed at a strain of 0.7. The maps exhibit two domains of peak efficiency from 750 to 950 °C. A *60 % peak efficiency occurs at 800-850 °C/0.001-0.010 s^(-1). The other peak efficiency of *60 % occurs at C950 °C/0.001-0.010 s^(-1), which can be considered to be the optimum condition for high-temperature working of this alloy.However, at strain rates of higher than 1.000 s^(-1)and deformation temperatures of 750 and 950 °C, clear process flow lines and bands of flow localization occur in the hightemperature deformation process, which should be avoided in Ti555211 alloy hot processing. The mechanism in stability domain and instability domain was also discussed.
基金supported by the Fundamental Research Funds for the Central Public Welfare Research Institutes (No.TKS20200311)。
文摘Cu_2NiSnS_4 nanoparticles were prepared for the first time using a facile solid-phase process at a temperature of 180 °C. The crystalline structure, morphology and optical properties of the Cu_2NiSnS_4 nanoparticles were characterized by means of X-ray diffraction(XRD), field emission scanning electron microscopy(FESEM), transmission electron microscope(TEM) and ultraviolet-visible(UV-vis) spectrophotometer. The band gap and conversion efficiency of Cu_2NiSnS_4 nanoparticles were studied at various temperature. The results showed that the Cu_2NiSnS_4 nanoparticles exhibited an optimum band gap of 1.58 e V and a conversion efficiency of 0.64% at 180 °C, indicating that it maybe be useful in low-cost thin film solar cells.
基金supported by the National Natural Science Foundation of China (No. 50775051) the Youth Technology Speciality Fund of Harbin (No.2008RFQXG052)
文摘The relationship between microstructure evolution and coefficient of thermal expansion (CTE) of 7A09 aluminum alloy was investigated in this paper. Differential scanning calorimetry (DSC) was combined with transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM) to investigate microstructure evolution taking place in 7A09 aluminum alloy during heating and cooling process. The corresponding CTE curves of the 7A0g alloy were recorded by thermal dilatometer. Results indicated that GPII zones and Ur phase were main precipitates in the highest strength tempered (T6) 7A09 alloy. The r/phase was the main participate in 7A09 alloy during the cooling process. The nonlinear dependency existed between CTE and temperature in both changing temperature processes. During the heating process, obvious additional contraction of alloy volume was directly caused by phase transition, such as dissolution of η' phase, transition from η' to η phase and dissolution of η phase. The additional contraction could slow down the increase of CTE greatly and be expressed in the nonlinearity of CTE curve. Volume and energy changes of alloy system influenced the variation trend of CTE directly, which was caused by the precipitation of U phase during the cooling process. These effects were revealed by the corresponding nonlinear change of CTE.
基金the funding support of the Zukunftsfonds Steiermark with funds from the province of Styria,Austria,Grant No.GZ:ABT08-189002/2020 PN:1305.
文摘Since pyrometallurgical approaches on lithium ion battery recycling are not yet capable of recovering lithium but only nickel,cobalt and manganese,the Chair of Thermal Processing Technology at the Montanuniversitaet Leoben started to investigate experimental reactor concepts on their suitability to overcome this major drawback.Therefor,the general behaviour of currently used cathode materials under reducing conditions and high temperatures is of great interest.This work expands previous performed heating microscope experiments by thermogravimetric analysis(TGA)to characterize the reactions that are responsible for certain changes in the cathode materials.By comparing the superficial changes of the samples in the heating microscope with the corresponding data from the TGA,it was possible to identify the temperature zones in which reduction reactions occured.For all investigated cathode materials,the reduction reactions started at technically feasible temperatures of approx.1000◦C,which is favorable for the desired recycling process.On the other hand,this is some hundred degrees higher than the temperature at which first changes in the heating microscope could be observed and indicates that there are changes in the material before the reduction starts.Therefore,the results also emphasize the need for further analysis to clarify this offset and to complete the thermal characterisation of the cathode materials.
基金supported by the PhD Student Innovation Program of Beijing University of Technology(No.bcx-2009-015)
文摘Using the multiple-parameter Monte Carlo method, the effectiveness of the dual threshold voltage technique (DTV) in low power domino logic design is analyzed. Simulation results indicate that under significant temperature and process fluctuations, DTV is still highly effective in reducing the total leakage and active power consumption for domino gates with speed loss. Also, regarding power and delay characteristics, different structure domino gates with DTV have different robustness against temperature and process fluctuation.
文摘This paper presents the design and measured performance ofa wideband amplifier for a direct conversion satellite tuner. It is composed of a wideband low noise amplifier (LNA) and a two-stage RF variable gain amplifier (VGA) with linear gain in dB and temperature compensation schemes. To meet the system linearity requirement, an improved distortion compensation technique and a bypass mode are applied on the LNA to deal with the large input signal. Wideband matching is achieved by resistive feedback and an off-chip LC-ladder matching network. A large gain control range (over 80 dB) is achieved by the VGA with process voltage and temperature compensation and dB linearization. In total, the amplifier consumes up to 26 mA current from a 3.3 V power supply. It is fabricated in a 0.35μm SiGe BiCMOS technology and occupies a silicon area of 0.25 mm^2.
文摘The 10MW high temperature gas-cooled reactor test module (HTR-10) is currently under construction.One of its objectives is to develop high temperature process heat applications. To realize this target, various high temperature gas-cooled reactor (HTGR) process heat applications have been analyzed. This paper briefly describes the possibilities and experimental schemes for using the HTR-10 for process heat application studies.